In various embodiments, an engine crankshaft is disclosed. The engine crankshaft comprises a rear bearing journal. The rear bearing journal has an output end. The rear bearing journal defines a substantially cylindrical cavity extending from the output end into the rear bearing journal. The engine crankshaft may further comprise at least one torque sensor operatively coupled to the rear bearing journal. The at least one torque sensor is configured to generate a torque signal corresponding to a torque exerted on the rear bearing journal. The torque exerted on the rear bearing journal is indicative of a torque output of an engine.